Journal of Heredity 2004:95(2):119-126
© 2004 The American Genetic Association
Genetic Structure of an Apis dorsata Population: The Significance of Migration and Colony Aggregation
From the School of Biological Sciences, A12, University of Sydney, 2006 NSW, Australia (Paar and Oldroyd); Institute of Zoology, Karl-Franzens University, 8010 Graz, Austria (Paar and Kastberger); and Institute of Apiculture, 3293 Lunz, Austria (Huettinger). We thank D. K. Sharma and Chetri Bopal at Gauhati University for their assistance in Assam, India. The study was supported by the Austrian Science Foundation and the Australian Research Council. We thank Pierre Franck for help with the statistical analyses, and Keith Goodnight for advice on the use of his program Relatedness.
Address correspondence to Jürgen Paar, School of Biological Sciences, A12, University of Sydney, 2006 NSW, Australia, or e-mail: juergen_paar{at}aon.at.
Eight microsatellite loci were used to investigate the genetic structure of the giant honeybee (Apis dorsata) population in northeast India. This species migrates seasonally between summer and winter nesting sites, and queens appear to return to their previously occupied site. Furthermore, there is a strong tendency for colonies of this species to aggregate at perennially utilized nesting sites that may be shared by more than 150 colonies. These behavioral features suggest that colonies within aggregations should be more related than random colonies, but that the long-distance migration could act to minimize genetic differentiation both between geographical areas and within aggregations. Our genetic study supports these conjectures arising from natural history. A. dorsata aggregations are comprised of colonies that share more alleles than expected by chance. Although queens heading neighboring colonies are not close relatives, fixation indices show significant genetic differentiation among aggregation sites. However, there appears to be sufficient gene flow among aggregations to prevent high degrees of relatedness developing between colonies within aggregations. The results also suggest that there is significant population structuring between geographical regions, although the level of structuring caused by aggregation exceeds the differentiation attributable to geographic region.